A year ago, Susan Wojcicki was on stage to defend YouTube. Her company, hammered for months for fueling falsehoods online, was reeling from another flare-up involving a conspiracy theory video about the Parkland, Florida high school shooting that suggested the victims were \u201ccrisis actors.\u201d Wojcicki, YouTube\u2019s chief executive officer, is a reluctant public ambassador, but she was in Austin at the South by Southwest conference to unveil a solution that she hoped would help quell conspiracy theories: a tiny text box from websites like Wikipedia that would sit below videos that questioned well-established facts like the moon landing and link viewers to the truth. Wojcicki\u2019s media behemoth, bent on overtaking television, is estimated to rake in sales of more than $16 billion a year. But on that day, Wojcicki compared her video site to a different kind of institution. \u201cWe\u2019re really more like a library,\u201d she said, staking out a familiar position as a defender of free speech. \u201cThere have always been controversies, if you look back at libraries.\u201d Since Wojcicki took the stage, prominent conspiracy theories on the platform\u2014including one on child vaccinations; another tying Hillary Clinton to a Satanic cult\u2014have drawn the ire of lawmakers eager to regulate technology companies. And YouTube is, a year later, even more associated with the darker parts of the web. The conundrum isn\u2019t just that videos questioning the moon landing or the efficacy of vaccines are on YouTube. The massive \u201clibrary,\u201d generated by users with little editorial oversight, is bound to have untrue nonsense. Instead, YouTube\u2019s problem is that it allows the nonsense to flourish. And, in some cases, through its powerful artificial intelligence system, it even provides the fuel that lets it spread. READ ALSO |\u00a0Facebook CEO Mark Zuckerberg's new vision may not deter Washington as it weighs options Wojcicki and her deputies know this. In recent years, scores of people inside YouTube and Google, its owner, raised concerns about the mass of false, incendiary and toxic content that the world\u2019s largest video site surfaced and spread. One employee wanted to flag troubling videos, which fell just short of the hate speech rules, and stop recommending them to viewers. Another wanted to track these videos in a spreadsheet to chart their popularity. A third, fretful of the spread of \u201calt-right\u201d video bloggers, created an internal vertical that showed just how popular they were. Each time they got the same basic response: Don\u2019t rock the boat. The company spent years chasing one business goal above others: \u201cEngagement,\u201d a measure of the views, time spent and interactions with online videos. Conversations with over twenty people who work at, or recently left, YouTube reveal a corporate leadership unable or unwilling to act on these internal alarms for fear of throttling engagement. Wojcicki would \u201cnever put her fingers on the scale,\u201d said one person who worked for her. \u201cHer view was, \u2018My job is to run the company, not deal with this.\u2019\u201d This person, like others who spoke to Bloomberg News, asked not to be identified because of a worry of retaliation. YouTube turned down Bloomberg News\u2019 requests to speak to Wojcicki, other executives, management at Google and the board of Alphabet Inc., its parent company. Last week, Neal Mohan, its chief product officer, told The New York Times that the company has \u201cmade great strides\u201d in addressing its issues with recommendation and radical content. A YouTube spokeswoman contested the notion that Wojcicki is inattentive to these issues and that the company prioritizes engagement above all else. Instead, the spokeswoman said the company has spent the last two years focused squarely on finding solutions for its content problems. Since 2017, YouTube has recommended clips based on a metric called \u201cresponsibility,\u201d which includes input from satisfaction surveys it shows after videos. YouTube declined to describe it more fully, but said it receives \u201cmillions\u201d of survey responses each week. \u201cOur primary focus has been tackling some of the platform\u2019s toughest content challenges,\u201d a spokeswoman said in an emailed statement. \u201cWe\u2019ve taken a number of significant steps, including updating our recommendations system to prevent the spread of harmful misinformation, improving the news experience on YouTube, bringing the number of people focused on content issues across Google to 10,000, investing in machine learning to be able to more quickly find and remove violative content, and reviewing and updating our policies - we made more than 30 policy updates in 2018 alone. And this is not the end: responsibility remains our number one priority.\u201d In response to criticism about prioritizing growth over safety, Facebook Inc. has proposed a dramatic shift in its core product. YouTube still has struggled to explain any new corporate vision to the public and investors \u2013 and sometimes, to its own staff. Five senior personnel who left YouTube and Google in the last two years privately cited the platform\u2019s inability to tame extreme, disturbing videos as the reason for their departure. Within Google, YouTube\u2019s inability to fix its problems has remained a major gripe. Google shares slipped in late morning trading in New York on Tuesday, leaving them up 15 percent so far this year. Facebook stock has jumped more than 30 percent in 2019, after getting hammered last year. YouTube\u2019s inertia was illuminated again after a deadly measles outbreak drew public attention to vaccinations conspiracies on social media several weeks ago. New data from Moonshot CVE, a London-based firm that studies extremism, found that fewer than twenty YouTube channels that have spread these lies reached over 170 million viewers, many who where then recommended other videos laden with conspiracy theories. The company\u2019s lackluster response to explicit videos aimed at kids has drawn criticism from the tech industry itself. Patrick Copeland, a former Google director who left in 2016, recently posted a damning indictment of his old company on LinkedIn. While watching YouTube, Copeland\u2019s daughter was recommended a clip that featured both a Snow White character drawn with exaggerated sexual features and a horse engaged in a sexual act. \u201cMost companies would fire someone for watching this video at work,\u201d he wrote. \u201cUnbelievable!!\u201d Copeland, who spent a decade at Google, decided to block the YouTube.com domain. Micah Schaffer joined YouTube in 2006, nine months before it was acquired by Google and well before it had become part of the cultural firmament. He was assigned the task of writing policies for the freewheeling site. Back then, YouTube was focused on convincing people why they should watch videos from amateurs and upload their own. A few years later, when he left YouTube, the site was still unprofitable and largely known for frivolity (A clip of David, a rambling seven-year old drugged up after a trip to a dentist, was the second most-watched video that year.) But even then there were problems with malicious content. Around that time YouTube noticed an uptick in videos praising anorexia. In response, staff moderators began furiously combing the clips to place age restrictions, cut them from recommendations or pull them down entirely. They \u201cthreatened the health of our users,\u201d Schaffer recalled. He was reminded of that episode recently, when videos sermonizing about the so-called perils of vaccinations began spreading on YouTube. That, he thought, would have been a no-brainer back in the earlier days. \u201cWe would have severely restricted them or banned them entirely,\u201d Schaffer said. \u201cYouTube should never have allowed dangerous conspiracy theories to become such a dominant part of the platform\u2019s culture.\u201d Somewhere along the last decade, he added, YouTube prioritized chasing profits over the safety of its users. \u201cWe may have been hemorrhaging money,\u201d he said. \u201cBut at least dogs riding skateboards never killed anyone.\u201d Beginning around 2009, Google took tighter control of YouTube. It ushered in executives, such as sales chief Robert Kyncl, formerly of Netflix, for a technical strategy and business plan to sustain its exploding growth. In 2012, YouTube concluded that the more people watched, the more ads it could run\u2014and that recommending videos, alongside a clip or after one was finished, was the best way to keep eyes on the site. So YouTube, then run by Google veteran Salar Kamangar, set a company-wide objective to reach one billion hours of viewing a day, and rewrote its recommendation engine to maximize for that goal. When Wojcicki took over, in 2014, YouTube was a third of the way to the goal, she recalled in investor John Doerr\u2019s 2018 book Measure What Matters. \u201cThey thought it would break the internet! But it seemed to me that such a clear and measurable objective would energize people, and I cheered them on,\u201d Wojcicki told Doerr. \u201cThe billion hours of daily watch time gave our tech people a North Star.\u201d By October, 2016, YouTube hit its goal. That same fall, three Google coders published a paper on the ways YouTube\u2019s recommendation system worked with its mountain of freshly uploaded footage. They outlined how YouTube\u2019s neural network, an AI system that mimics the human brain, could better predict what a viewer would watch next. The research notes how the AI can try to suppress \u201cclickbait,\u201d videos that lied about their subject and lost viewer\u2019s attention. Yet it makes no mention of the landmines\u2014misinformation, political extremism and repellent kid\u2019s content\u2014that have garnered millions and millions of views and rattled the company since. Those topics rarely came up before the 2016 U.S. election. \u201cWe were so in the weeds trying to hit our goals and drive usage of the site,\u201d said one former senior manager. \u201cI don\u2019t know if we really picked up our heads.\u201d YouTube doesn\u2019t give an exact recipe for virality. But in the race to one billion hours, a formula emerged: Outrage equals attention. It\u2019s one that people on the political fringes have easily exploited, said Brittan Heller, a fellow at Harvard University\u2019s Carr Center. \u201cThey don\u2019t know how the algorithm works,\u201d she said. \u201cBut they do know that the more outrageous the content is, the more views.\u201d People inside YouTube knew about this dynamic. Over the years, there were many tortured debates about what to do with troublesome videos\u2014those that don\u2019t violate its content policies and so remain on the site. Some software engineers have nicknamed the problem \u201cbad virality.\u201d Yonatan Zunger, a privacy engineer at Google, recalled a suggestion he made to YouTube staff before he left the company in 2016. He proposed a third tier: Videos that were allowed to stay on YouTube, but, because they were \u201cclose to the line\u201d of the takedown policy, would be removed from recommendations. \u201cBad actors quickly get very good at understanding where the bright lines are and skating as close to those lines as possible,\u201d Zunger said. His proposal, which went to the head of YouTube policy, was turned down. \u201cI can say with a lot of confidence that they were deeply wrong,\u201d he said. Rather than revamp its recommendation engine, YouTube doubled down. The neural network described in the 2016 research went into effect in YouTube recommendations starting in 2015. By the measures available, it has achieved its goal of keeping people on YouTube. \u201cIt\u2019s an addiction engine,\u201d said Francis Irving, a computer scientist who has written critically about YouTube\u2019s AI system. Irving said he has raised these concerns with YouTube staff. They responded with incredulity, or an indication that they had no incentives to change how its software worked, he said. \u201cIt\u2019s not a disastrous failed algorithm,\u201d Irving added. \u201cIt works well for a lot of people, and it makes a lot of money.\u201d Paul Covington, a senior Google engineer who coauthored the 2016 recommendation engine research, presented the findings at a conference the following March. He was asked how the engineers decide what outcome to aim for with their algorithms. \u201cIt\u2019s kind of a product decision,\u201d Covington said at the conference, referring to a separate YouTube division. \u201cProduct tells us that we want to increase this metric, and then we go and increase it. So it\u2019s not really left up to us.\u201d Covington did not respond to an email requesting comment. A YouTube spokeswoman said that, starting in late 2016, the company added a measure of \u201csocial responsibility\u201d to its recommendation algorithm. Those inputs include how many times people share and click the \u201clike\u201d and \u201cdislike\u201d buttons on a video. But YouTube declined to share any more detail on the metric or its impacts. Three days after Donald Trump was elected, Wojcicki convened her entire staff for their weekly meeting. One employee fretted aloud about the site\u2019s election-related videos that were watched the most. They were dominated by publishers like Breitbart News and Infowars, which were known for their outrage and provocation. Breitbart had a popular section called \u201cblack crime.\u201d The episode, according to a person in attendance, prompted widespread conversation but no immediate policy edicts. A spokeswoman declined to comment on the particular case, but said that \u201cgenerally extreme content does not perform well on the platform.\u201d At that time, YouTube\u2019s management was focused on a very different crisis. Its \u201ccreators,\u201d the droves that upload videos to the site, were upset. Some grumped about pay, others threatened openly to defect to rival sites. Wojcicki and her lieutenants drew up a plan. YouTube called it Project Bean or, at times, \u201cBoil The Ocean,\u201d to indicate the enormity of the task. (Sometimes they called it BTO3 \u2013 a third dramatic overhaul for YouTube, after initiatives to boost mobile viewing and subscriptions.) The plan was to rewrite YouTube\u2019s entire business model, according to three former senior staffers who worked on it. It centered on a way to pay creators that isn\u2019t based on the ads their videos hosted. Instead, YouTube would pay on engagement\u2014how many viewers watched a video and how long they watched. A special algorithm would pool incoming cash, then divvy it out to creators, even if no ads ran on their videos. The idea was to reward video stars shorted by the system, such as those making sex education and music videos, which marquee advertisers found too risqu\u00e9 to endorse. Coders at YouTube labored for at least a year to make the project workable. But company managers failed to appreciate how the project could backfire: paying based on engagement risked making its \u201cbad virality\u201d problem worse since it could have rewarded videos that achieved popularity achieved by outrage. One person involved said that the algorithms for doling out payments were tightly guarded. If it went into effect then, this person said, it\u2019s likely that someone like Alex Jones\u2014the Infowars creator and conspiracy theorist with a huge following on the site, before YouTube booted him last August\u2014would have suddenly become one of the highest paid YouTube stars. Wojcicki pitched Project Bean to Google\u2019s leadership team in October of 2017. By then, YouTube and other social media sites faced the first wave of censure for making \u201cfilter bubbles\u201d\u2014directing people to preexisting beliefs, then feeding them more of the same. Wojcicki\u2019s boss, Sundar Pichai, turned down YouTube\u2019s proposal because, in part, he felt it could make the filter bubble problem worse, according to two people familiar with the exchange. Another person familiar with the situation said the effort was shelved because of concerns that it would overly complicate the way creators were paid. YouTube declined to comment on the project. In November of 2017, YouTube finally took decisive action against channels pushing pernicious videos, cutting thousands off from receiving advertisements or from the site altogether virtually overnight. Creators dubbed it \u201cThe Purge.\u201d The company was facing an ongoing advertiser boycott, but the real catalyst was an explosion of media coverage over disturbing videos aimed at children. The worst was \u201cToy Freaks,\u201d a channel where a father posted videos with his two daughters, sometimes showing them vomiting or in extreme pain. YouTube removed Toy Freaks, and quickly distanced itself from it. But the channel hadn\u2019t been in the shadows. With over eight million subscribers, it had been reportedly among the top 100 most watched on the site. These types of disturbing videos were an \u201copen secret\u201d inside the company, which justified their existence often with arguments about free speech, said one former staffer. YouTube had also wrestled with another debate around its programming for kids. Before the launch of a dedicated app for minors, YouTube Kids, several people advocated that the company only offer hand-picked videos in the service to avoid any content kerfuffles. Those arguments lost, and the app has since picked videos algorithmically. YouTube did plow money into combating its content problems. It hired thousands more people to sift through videos to find those that violated the site\u2019s rules. But to some inside, those fixes took too long to arrive or paled next to the scale of the problem. As of 2017, YouTube\u2019s policy for how content moderators handle conspiracy theories didn\u2019t exist, according to a former moderator who specialized in foreign-language content. At the end of the year, fewer than twenty people were on the staff for \u201ctrust and safety,\u201d the unit overseeing content policies, according to a former staffer. The team had to \u201cfight tooth and nail\u201d for more resources from the tech giant, this person said. A YouTube spokeswoman said that the division has grown \u201csignificantly\u201d since but declined to share exact numbers. In February of 2018, the video calling the Parkland shooting victims \u201ccrisis actors\u201d went viral on YouTube\u2019s trending page. Policy staff suggested soon after limiting recommendations on the page to vetted news sources. YouTube management rejected the proposal, according to a person with knowledge of the event. The person didn\u2019t know the reasoning behind the rejection, but noted that YouTube was then intent on accelerating its viewing time for videos related to news. However, YouTube did soon address its issues around news-related content. Last July, YouTube announced it would add links to Google News results inside of YouTube search, and began to feature \u201cauthoritative\u201d sources, from established media outlets, in its news sections. YouTube also gave $25 million in grants to news organizations making videos. In the last quarter of 2018, YouTube said it removed over 8.8 million channels for violating its guidelines. Those measures are meant to help bury troubling videos on its site, and the company now points to the efforts as a sign of its attention to its content problems. Yet, in the past, YouTube actively dissuaded staff from being proactive. Lawyers verbally advised employees not assigned to handle moderation to avoid searching on their own for questionable videos, like viral lies about Supreme Court Justice Ruth Bader Ginsburg, according to one former executive upset by the practice. The person said the directive was never put in writing, but the message was clear: If YouTube knew these videos existed, its legal grounding grew thinner. Federal law shields YouTube, and other tech giants, from liability for the content on their sites, yet the companies risk losing the protections of this law if they take too active an editorial role. Some employees still sought out these videos anyway. One telling moment happened around early 2018, according to two people familiar with it. An employee decided to create a new YouTube \u201cvertical,\u201d a category that the company uses to group its mountain of video footage. This person gathered together videos under an imagined vertical for the \u201calt-right,\u201d the political ensemble loosely tied to Trump. Based on engagement, the hypothetical alt-right category sat with music, sports and gaming as the most popular channels at YouTube, an attempt to show how critical these videos were to YouTube\u2019s business. A person familiar with the executive team said they do not recall seeing this experiment. Still, as the company\u2019s algorithms continued to cause headaches, knives have come out. Some former staff fault Wojcicki, who inherited a business oriented toward netting more views and failed to shift its direction meaningfully. Others blame Kyncl, YouTube\u2019s business chief, who oversees creator relations and the content moderation decisions. While Wojcicki and Neal Mohan, YouTube\u2019s product head, have given several public addresses on content-related issues, Kyncl has been less vocal on the matter. Even so, the executive has made other public moves that are viewed by some inside Google as self-promotional. Last August, a week after a damning report on the prevalence of extremist videos on YouTube, he modeled a suit in an ad by luxury brand Brioni. That ad, released amid YouTube\u2019s troubles, raised concerns about Kyncl\u2019s priorities among several employees at Google, according to one person there. Representatives for the company and Kyncl declined to comment. This past January, YouTube followed former Google employee Zunger\u2019s advice and created a new tier for problematic videos. So-called \u201cborderline content,\u201d which doesn\u2019t violate the terms of service, can stay on the site, but will no longer be recommended to viewers. A month later, after a spate of press about vaccination conspiracies, YouTube said it was placing some of these videos in the category. In February, Google also released a lengthy document detailing how it addresses misinformation on its services, including YouTube. \u201cThe primary goal of our recommendation systems today is to create a trusted and positive experience for our users,\u201d the document reads. \u201cThe YouTube company-wide goal is framed not just as \u2018Growth\u2019, but as \u2018Responsible Growth.\u2019\u201d The company has been applying the fix Wojcicki proposed a year ago. YouTube said the information panels from Wikipedia and other sources, which Wojcicki debuted in Austin, are now shown \u201ctens of millions of times a week.\u201d A 2015 clip about vaccination from iHealthTube.com, a \u201cnatural health\u201d YouTube channel, is one of the videos that now sports a small gray box. The text links to a Wikipedia entry for the MMR vaccine. Moonshot CVE, the London-based anti-extremism firm, identified the channel as one of the most consistent generators of anti-vaccination theories on YouTube. But YouTube appears to be applying the fix only sporadically. One of iHealthTube.com's most popular videos isn\u2019t about vaccines. It\u2019s a seven-minute clip titled: \u201cEvery cancer can be cured in weeks.\u201d While YouTube said it is no longer recommends the video to viewers, there is no Wikipedia entry on the page. It has been viewed over 7 million times.